Motor vehicle



April 13, 1937. J. o. HEINZE 2,076,722

MOTOR VEHICLE M Filed April 10, 1935 4 sheetsslpeet J.

ATTORNEYS J. O. HE INZE April 13, .1937.

MOTOR VEHICLE Filed April 10, 1935 4 Sheets-Sheet 2 l 1 a v w VII/ l l Vw INVENT OR.

ATTORNEYS J. o. HEINZ E MOTOR VEHICLE April is, 1937.

Filed April 10, 1955 4 Sheets-Sheet 3 Pa sed Apr. -13, 1937 UNiTEDSTATES MOTOR VEHICLE John 0. Helnze, Detroit, Micln, assignor to HeinzeDevelopment Company, Detroit, Mich., a corporation of MichiganApplication April 10, 1935, Serial No. 15,662

9 Claims. (Cl. 180-21) This invention relates to self propelledvehicles, and more particularly to an arrangement of driving and drivenground wheels and power generating and power transmittinginstrumentalities in such vehicles. 1

Present day trend in automobiles is toward what is known as streamlining but with the present day arrangement of front steering groundwheels and rear driving wheels driven by a prime mover positioned at theforward end of the vehicle and from which power is transmitted to saidrear wheels, complete stream lining is impossible from a practicalstandpoint.

An object of the present invention is to provide an arrangement, withina motor vehicle, of ground wheels, power generator, and drive forcertain of said wheels, whereby complete stream lining of the vehicle ismade possible; and to provide an arrangement whereby even distributionof weight is secured. A further object is to provide an arrangementwhereby better ground contact of driving wheels and bettermaneuverability of the vehicle is secured through the relativearrangement ofdriving and steering ground wheels,

and whereby the riding qualities of the vehicle are enhanced.

It is also an object to provide an arrangement permitting of andfacilitating individual spring suspension of all ground wheels, and theindividual driving of the driving wheels; and to provide for thelocation amidships, of a prime mover or internal combustion powergenerator, and the transmission of power therefrom to drive each drivingwheel individually, including an air compressor driven by the engine tosupply air under pressure to motors individual to the driving wheels. v

It is also an object to facilitate steering and enhance maneuverability,and at the same time permit complete stream lining of the body of thevehicle, by providing a single steering ground wheel adjacent theforward end of the vehicle and a similar single steering ground wheeladjacent the rear end thereof, the driven ground wheels being located atthe sides of the vehicle, midway between said ends and midway betweensaid steering wheels so that all mechanism including the ground wheels,may be located within the confines of the chassis frame which .fol-

lows the outlines of the streamlined body. Further objects are toprovide. a form of spring suspension especially adapted for individualsuspension of each of the several ground wheels within the particularconstruction and arrangement shown, and to provide certain other new andful features in steering and control systems especially adapted forsimultaneous steering of the steering wheels and for control of flow ofair under pressure to said wheel motors from said compressor; and toprovide certain other new 5 and useful features in the construction,arrangement and combination of parts, all as hereinafter set forth,reference being had to the accompanying drawings wherein is a plan viewof a chassis of a motor 10 ve cle illustrative of an embodiment of thepresent invention;

Fig. 2 is a side elevation of Fig. 1 and illustrating, in dot and dashlines, a vehicle body in place upon the chassis; 15

Fig. 3 is an enlarged transverse section upon the line 3-3 of Fig. l; 1i

Fig. 4. is a sectional detail upon the line 6-5 of Fi 3;

Fig. 5 is a section upon the line 5-5 of Fig. 3:

Fig. 6 is an enlarged section upon the line 6-6 of Fig. l;

Fig. 7 is a section upon the line 7-1 of Fig. 6;

Fig. 8 is a section substantially upon the line 8-8 of Fig. 6; 25

Fig. 9 is an enlarged sectional elevation of a bellows structure formingpart of the spring suspension mechanism shown in Fig. 10;

Fig. 10 is a side elevation, with parts in section, upon the line it-iiiof Fig. l, of a spring sus- 30 pension showing a steering ground wheelin vertical section pivotally connected thereto for steering movement;and

Fig. 11 is a diagrammatic illustration of a system for supplying airunder pressure to the motors. 35 on the drive wheels, from an aircompressor drlv-' en by an internal combustion engine.

As shown more particularly in Fig.4, the chassis frame indicated as awhole by the numeral I, outlines, in "plan view, the entire vehicle, the40 lower edge of the vehicle body, indicated by the numeral 2 and shownin dot and-dash lines in Fig. 2, conforming strictly to the outline ofsaid frame'with no parts of the mechanism, including the ground wheels,projecting beyond the con- 45 fines of said frame outline, and. as thesides of this frame are curved and converge toward the front and rearends of the vehicle, terminating in substantially sharp rounded ends,complete stream-lining of the vehicle is secured. v 50 This chassisframe I comprises the outer curved channel members 3 connected bylongitudinal parallel channel frame members 4, parallel cross members 5and transverse members 6, all rigidly secured together in any suitable55 the ends thereof to accommodate side driving wheels 1, one at eachside of the vehicle, each wheel being individually connected to eachlongitudinal frame member 4 inwardly from the extreme sides of theframe, by a pair of top arms 3 and a pair of bottom arms 9, the top armsI being connected and pivotally mounted intermediate their ends, uponsaid frame member 4 by means of a pivot rod l0 mounted in bearingbrackets ll mounted upon and extending upwardly from the upper side ofsaid frame member. These arms 8 extend beyond their pivotal support withtheir inner free ends pivotally con-' nected, as at l2 to the upper endsof bellows members, each indicated as a whole by the numeral I 3, eachbellows serving the purpose of a compression spring to resist upwardmovement of the wheel 1 to the hub portion i 4 of which wheel the outerends of the arms 8 are pivotally attached, as at l5, and the inner endsof arms 9 of the lower pair, are pivotally connectedzas at l3 to theframe in any suitable manner'and extend outwardly beneath the framemember 4 to permit of suitable pivotal connection IT with the hub i4.The upper and lower pairs of supporting arms' thus swing in substantialparallel ism against the resistance of the two bellows,

under load on the chassis frame, permitting the wheel 1 to movevertically relative to the frame and thus providing an individualspringsuspension for each of the two driving wheels so that one of thesewheels 1 may move upwardly relative to the frame entirely independent ofthe other; and to limit such movement of the arms of both pairs,relative to the frame, these arms are each formed with a laterallyextending lug i8 intermediate its ends to engage limit bumper blocks i9.carried by brackets 20 secured to the outer side of the frame members 4.

Each driving wheel 'I'is mounted upon its fixed hub l4 through themedium of a driven shaft, these wheels being each provided with a brakedrum 2| and brake shoes indicated at 22, all

arranged in an old and well known manner, and

preferably, the hub l4 for each wheel I and which is yieldingly carriedupon the outer ends of the arms 9 and 9 as described, is preferably ofoutwardly tapering conical form and provided, adjacent its inner andouter-ends with '56 bearings 23 for a short drive shaft 24 provided witha gear drum 25 on its inner end, the wheel 1 being keyed or otherwisefixed to the extreme outer end of said shaft. Within the drum 25 of eachwheel shaft 24 is an internal ring gear I so 28 (see Fig. '4) and idlergears 21 for transmittingjmotion from a pinion 23 on the outer end of aneccentric shaft 29 of a rotary type of air' motor indicated as a wholeby the numeral 30, each ofthese motors comprising a cylindrical '65casing 3| divided by transverse partitions into a plurality ofcylinders, each cylinder containing a piston 32 of less diameter thanthe internal diameter of its cylinder,- whereby by mounting each piston32 upon an eccentric portion 33 of 70 the shaft 29 and anchoring thepiston at one side, to thecasing by means of a battle member 34projecting into a slot in the piston from the I wall of the cylinder,and providing a pivotal Joint member 35 within said slot within whichsaid 7 baflle may slide, the admission of air under pressure into eachcylinder through an inlet pipe 33 at one side of said baille and theexhaust of air through an outlet pipe 31 at the other side of saidbaiile, will impart a swinging movement to each piston within itscylinder and a sliding 5 movement thereof upon said baflle, so that airpressure will hold said piston agai'nst the wall of its cylinderthroughout its eccentric movement and rotary motion will be imparted tosaid shaft 29 through the offset in one direction of the ec- 10 centric33 upon which one piston is mounted,- and the offset in an oppositedirection of the eccentrics upon which other pistons are'mounted, theone piston being thus substantially at the end of its power stroke whenthe other pis- 15 shown being, however, particularly adapted for thepurpose and to the present construction of individual wheel mounting.

Tosupply air under pressure to each of the rotary motors .30 for drivingthe drive wheels 1, a prime mover or power generator, preferably in theform of a doubleopposed type of internal combustion engine 38, as shown,is supported by brackets 39 on the frame members 4 and within 30 theplane of the frame, between said members with the longitudinal axis ofthe cylinders of said engine and the longitudinal axes of said airmotors 39 substantially in alignment, thus 10- cating said engine midwaybetween the drive 30 wheels 1 and at a minimum height from theground sothat the power generating, the driving, the spring suspension, andsubstantially all mechanism will be located mainly within the plane ofthe chassis frame and beneath, or 'main- 40 ly beneath the floor of the,bodypf the car, and the greater part of the weight of all of theoperating mechanism of' the vehicle will be carried by the chassisframe, midway of the ends thereof and directly between the two drivewheels, at 45 the sides of the vehicle, whereby the preponderance ofload is taken by thesedriving wheels and evenly distributedtherebetween, the center of gravity of the entire vehicle being thuslocated midway between these side driving wheels 5 the shaft of saidpump, which pump is of substantially the same construction as the airmotors 39, the extended end of the crank shaft 4i being provided with aplurality of eccentrics 42 corresponding to the eccentrics33 of said airmotors, a plurality of pistons similar to the pistons 32,

a baflle member 44 similar to the baille 34, air-165 tending into a slotin' each piston arid slidable through a pivot member 45 mounted in saidslot. of eachpiston. The casing or wall of each cylinder is providedwith an inlet passage at one side of each baflle'and an outlet passageat the other side, these passages opening into a manifoldjcas-' ing 46,divided by a wall to form an inlet chamber and an outlet chamber foreach cylinder, each outlet chamber being provided with a valve 41therein to seat over the outer end of each outlet passage and preventair under pressure from flowing back into the cylinder from said outletchamber. The wall of the casing forming the several cylinders, is formeddouble to provide a water jacket 48 surrounding the several cylinders,and leading to the inlet chambers of the manifold 46 is an inlet pipe 49and leading from the outlet chamber is a pipe 50, both pipes leading toa control valve casing Si in which casing is a rotary valve 52. Leadingfrom the lower part of said valve casing as shown in Fig. '7, areconduit pipes 53 which extend transversely of the chassis frame topoints adjacent the two motors 30 for driving the drive wheels I, andare connected to the pipes 36 of said motors by short flexible tubularsections 54 as shown in Fig. 1 and diagrammatically illustrated in Fig.11; and leading from the upper part of said casing 5! are similarconduit pipes 55 connected attheir outer ends by like flexible sections54 to the pipes, 31 of said motors. These conduits 53 and 55 are thusdirectly connected to the motors 30 to deliver fluid under pressure fromsaid air pump 40 to said motors and to conduct such fluid discharged bysaid motors, back to said pump, said flexible connections 54 permittingfree movement of said motors relative to said conduits upon flexure ofthe spring suspensions for the driving wheels I.

To control the flow of fluid to and from the pump 40, the rotary valve52 is formed with passages 56 so arranged that when said valve 52 isturned to the position shown in Figs. 7 and 11, air or fluid will flowunder full pressure through outlet pipe 5B of the pump and through oneof the passages 55 of the valve, into the pipes 53 and thence to theinlet sides or pipes 36 of the motors, and the discharge of said motorswill flow through the pipes 55, and through the other passage 56 of thevalve, to the pipe 69 and back to the inlet side of the pump. Reversalof the direction of drive of the motors, may be effected by giving thevalve 52 a quarter turn, thus connecting the pump outlet pipe 50 withthe pipes 55, and con necting the pipes 53 with the intake pipe 69 ofthe pump. The fluid is thus circulated in a closed circuit through thepump and motors, and

when desired, communication between pump and motors may be cut off bygiving said valve an eighth of a turn, thus positioning the valvepassages 55 with their ends intermediate the opening in the valve easinginto which the several pipes d9, 59, $3 and 55 open.-

In order to provide open flow circuits through said motors when thecontrol valve is in intermediate position with the pump out off fromcommunicating with said motors, said valve is formed, intermediate thepassages 55, with crossover passages 57 arranged at right angles to eachother so that when said valve is turned to this intermediate position,the pipes 53 will be connected by one of said passages 51 with the pipes55 and an open fiow circuit for each motor 'will be provided, so thatif, at the time, the vehicle should be progressing in either directionand the motors thus driven by the rolling of the driving wheels i on theground, the fluid will be free to circulate through-the motors withoutcreating a back pressure which would resist rotation of the motors andthus exert a braking action on said wheels. This open flow circuit thuspermits the vehicle to coast and provides for what is known as freewheeling. Z

Where the system is operated upon an elastic or compressible fluid. suchas air, when the system is put into operation after it has been at rest,the

control valve 52.

starting of the pumps, will, due to the compressibility of the air inthesystem, create a partial vacuum in that side of the system which isconnected to the intake side of the pump, due to the I 11, is providedin the inlet pipe 49 of the pump or any other suitable part of theintake side of the system, said valve being arranged to be seated toclose the same, by pressure within the pipe or system and to open andadmit atmospheric .air .when'a partial vacuum is created in said pipe orsystem.

The control valve 52 is preferably of cylindrical form with a stub-shaftprojecting from one end thereof, and to the outer end of this stub, anoperating arm 59 (Fig. 6) is secured. Connected to the free end of thisarm, is a connecting rod 80, the opposite end of which rod is connectedto an arm 5| on the lower end of a rod or shaft 82 attached in anysuitable manner to a steering column 53 to extend parallel therewith tonear the upper end thereof below a steering wheel 54 thereon where saidrod 62 is provided with a hand control lever or handle 65 for oper--ation by the driver of the vehicle to operate the Due to the tapering orpointed end formations of the chassis frame, this shape of frame lendsitself particularly to the location within said ends adjacent the pointsor extreme ends thereof, of steering ground-wheels 55, and thisarrangement of a single ground steering-wheel at each end of thevehicle, greatly facilitates the steering of the vehicle and itsmaneuverability as either end may be swung laterally in either directionand the other end simultaneously in an opposite direction, each wheelbeing mounted to rotate freely upon a spindle 5'! which is mounted forsteering movement, upon the-upwardly extending axis of a head 68 withwhich said spindle is integrally formed, all as shown in detail in Fig.10.

A spring suspension quite similar to the spring suspension for eachdriving wheel-1, is provided for each steering wheel 56, this suspensioncom-.

prising a pair of upper arms 69-10 having a coon pivotal connection itat their outer ends to the upper end of the spindle head 58, and a lowerpair of arms l2 and 13 having a common pivotal connection id at theirouter ends, to the lower end of said head as.

At theirinner ends, the lower arms are pivotally connected at E5 to theunder side of the frame member 8, and the upper arms 69-10 are pivotally attached to the upper side of the frame member 6 and connected toturn together, by a rod '36 mounted in bearings on said frame memberwith the inner end of the arm in extended beyond such pivot rod andpivotally at-- tached at its inner end, as at ii to the upper end of abellows indicated as a whole by the numeral '58.. The wheels S6 are thuseach pivotally connected to the chassis frame through the medium of twoparallel pairs of arms with up and down swinging movement of these armsyieldingly resisted by the bellows l8, and as each wheel is pivotallyconnected to the outer ends of these pairs of arms, to turn upon theupwardly extending axis of the pivotal connection of its spindle head 58with said arms, by providing each head for each wheel with a laterallyextending rigid steering arm I9 and pivotally connecting the free endsof said arms by means of universal joints I0 parallel, hollow outwardlyprojecting ribs 86 with interposed external grooves with metal rings 81with the outer ends of connecting rods 8|, and connecting the inner endsof said connecting rods by means of universal joints 8! to the upperends of rigid arms 88 on a longitudinally shiftable rod 84 mounted inbearing brackets on the frame member 4 and extending parallel therewithfrom front to rear of the chassis the two steering wheels 68 maybe-simultaneously turned in opposite directions by the shifting of saidrod 84, to direct the front end of the vehicle laterally in onedirection and direct the re'ar end of the vehicle simultaneously in anopposite lateral direction and to so shift the rod 84 in steering thevehicle any suitable connection is provided between said rod and thelower end of the shaft of the steering column, upon the upper end ofwhich shaft the steering wheel 64 is secured.

In detail, the two bellows II for the spring suspension of each drivingwheel I and the bellows 18 for the spring suspension of each steeringwheel 86, comprises, as shown in Fig. 9, a bellows proper, formed with aflexible wall 85, preferably of rubber, which wall is folded .to formseated-in the bottoms of ,said grooves to prevent undue expansion of thebellows and to maintain its cylindrical shape. The lower end of eachbellows is formed with an air chamber 88 and this chamber of each of theseveral bellows is in free communication with an air tank 88 (seeFig. 1) for the purpose of increasing the volume of air acted uponwhenthe bellows is compressed under load, thus obviating the necessity for abellows of extended length, and preferably, as shown in Fig. 9, thebellows is inclosed, except its upper end to which the operating arm isattached, by a sheet metal cup 98 or casing to protect' the bellows andto form a support therefor. As shown in Fig. 1, the engine 38 isprovided with an exhaust muiiler 9| supported within the chassis frameat the rear of the engine with its outlet end provided with a V-shapedoutlet pipe 82 to direct the exhaust laterally away from the sides ofthe rear steering wheel 68.

. The service brakes including brake drum 2| and shoes 22 in each of thetwo drive wheels I, are operated in the usual manner by a foot pedal 83operatively connected to transverse shafts 94, one for transmittingoperating power to each .brake, and said pedal being connected to theadjacent ends of said shafts through an interposed equalizer, indicatedat 8 5, the outer ends of said shafts 84 being connected by rods 86 inthe usual or any suitable manner to the brake shoe actuating meanscarried by the wheels.

The described arrangement of driving wheels atopposite sides of thevehicle midwaybetween a single steering ground wheel at each end 'ofthevehicle, lends itself particularly to its application to a chassis frameoutlining a body of complete stream line contour, i, e., a body curvedfrom end to end' and terminating in comparatively sharp but rounded endsin plan view. This application is made possible due to the fact that thesingle wheels may be located wholly within the outlines of these pointedends of the chassis frame without'projecting beyond the outlines of saidends, and the side driving wheels may be located within recesses in thewidest part of the frame, thus bringing all ground wheels within theoutline of theframe and body.

By locating the prime mover-or. internal combustion engine midwaybetween the side driving wheels and at both the longitudinal and transverse center of the chassis, a preponderance of the weight of thechassis is centralized and a;

balanced effect secured. Further, the arrangement lends itselfparticularly to individual or independent spring suspension of allground wheels, thus giving the maximum in riding qualities to thevehicle; and by providing individual motor drive for each drive wheel,weight is reduced by dispensing with the necessity for change speed atedmotors 38 is such as 'to particularly adapt them for direct mountingupon the disc wheels 1,

and the arrangement of rotary air pump direct connected to engine crankshaft, with a single control valve to control the circulation of airfrom pump to motors and back to pump, is such as to greatly simplify theconstruction and the control and the operation of the vehicle. Themaneuverability of the vehicle is greatly increased by the provision ofa single ground steering-wheel ateach end, the vehicle being thusmaneuvered by swinging it about a central point, thus making it.

possible to get into and out of a small space between parked cars, thestream line shape of the vehicle greatly enhancing such maneuverability.

While a particular construction and arrangement of power and controldevices has been shown, it will be understood that such construc-- tionand arrangement may be 'varied without departing from the spirit of myinvention and such changes are contemplated.

What I claim is:-

1'. In a motor vehicle, the combination of a chassis frame having curvedsidemembers forming the outline of the vehicle in plan view andconverging toward the ends of the frame/ground engaging driving wheels,said side members of said frame being'interrupted opposite said drivingwheels and said frame including transverse members at front and rear ofsaid wheels and longitudinal members spaced from the inner sides of saidwheels, a ground engaging steering wheel 1 between said sides of saidframe adjacent the places of convergence of said sides at each end ofsaid frame, means for yieldingly connecting said driving wheels to saidlongitudinal frame members inwardly from said wheels, means for drivingsaid driving wheels and permitting individual yielding movement of saidwheels, and means for turning said steering wheels simultaneously insteering the vehicle.

2.,In a motor vehicle, the combination of a chassis frame having sidescurved in plan view and converging toward each end of said frame to formpointed ends, said frame being adapted to support a body conforming inplan view to the outline of said frame to give stream lining, a groundengaging steering wheel within each pointed end of said frame and whollywithin the outline thereof in plan view, means for individually andyieldingly connecting each steering wheel to said frame, means forconnecting said 'ing connection foreach. of said driving wheels aovavsato said frame, and separate means for-driving each of said drivingwheels.

3. In a motor vehicle, the combination of a chassis frame, groundcontacting steering wheels,

is one at each end of said frame, ground contacting driving wheels, oneadjacent each side of said frame and midway of the ends thereof and eachpivotally connected to said frame inwardly from said wheel for movementindependently of the I other and of said frame, to provide for kneeaction of said wheels, a power plant mounted upon said frame betweensaid driving wheels, a separate motor unit carried by each driving wheeland movable therewith, flexible means on the frame for transmittingpower from said plant to drive each of said motors independently of theother and permit free movement of each connection of each wheel to saidframe, yieldable means for resisting movement of each of said steeringand driving wheels relative to said frame to-yieldingly support the loadof said frame upon said wheels, and means for simultaneously turningsaid steering wheels in opposite directions in steering the vehicle.

4. In a motor vehicle as characterized in claim 3 and wherein saidchassis frame comprises side .members curved in the direction of theirlength and converging toward the ends of the frame to outline a framewhich in plan view has pointed 3 ends and curved sides for the supportof a body stream lined in plan view, and wherein said steering wheelsare located within said pointed ends of said frame, and wherein saiddriving wheels are located inwardly of said frame outline at oppositesides of the frame and midway of the length thereof.

5. In a stream-lined motor vehicle, the combination of a chassis frameforming the outline of said vehicle in plan view, and having sidemembers curved in the direction of their length and converging towardeach other to form substantially pointed frame end portions, a bodyconforming in plan view to the outline of said frame, drivin rund-wheels connected to said frame inwardly from the sides thereof andmidway of the length of the vehicle to position said wheels whollywithin ,the said outline of the vehicle, steering ground-wheels eachpivotally supported to turn upon an upwardly extending axis, whollywithin the outline of each pointed end portion of said frame, means foroperatively connecting said steering wheels to turn the samesimultaneously in opposite directions, power means mounted upon eachdriving wheel at the inner sides thereof for driving the same, powergenerating means mounted on said frame centrally thereof midway betweensaid driving Wheels, and means for transmitting power from said powergenerating means to said power means on each driving wheel. so 6. In amotor vehicle as characterized in claim 2, and including powergenerating means on said frame midway between said driving wheels; andwherein said means for driving each of said driving wheels includes adriving unit mounted upon each driving wheel for movement therewith anda flexible connection to each driving unit to transmit power from saidpower generating means to permit free individual yielding movement ofeach driving wheel.

7. In a motor vehicle, as characterized in claim 2, and wherein saidchassis frame includes longitudinal frame members extending parallelwith and at a distance from the inner sides'of said ground wheels, andwherein said means for indi-' vidually connecting each of said wheels tosaid frame includes parallel arms pivotally connected at their outerends to the mounting structure of the adjacent wheel and adjacent theirinner ends to the upper and lower sides of said adjacent frame memberwith one of said arms extending inwardly beyond said frame member, andyieldable means connected to said extended end of said arm to resistupward swinging of the outer ends of said arms and wheel carriedthereby.

8. In a motor vehicle as characterized in claim 2 and wherein saidchassis frame includes longitudinal frame members spaced from one sideof said ground engaging wheels, and wherein said means for pivotallyconnecting each of said wheels to said chassis frame includes two pairsof arms with the arms of one pair pivotally connected to one of saidframe members at spaced apart points longitudinally of said member andwith said pairs of arms pivotally connected to a wheel mounting memberat vertically spaced points, whereby said mounting member is bracedagainst movement in the direction of the length of said frame andvertical swinging movement of said arms and up and down movement of saidwheel relative to said frame is permitted, and means foryieldingly'resisting said swinging .movement in one directiorn.

9. In a motor vehicle of the character described, the combination with achassis frame having longitudinal members and ground wheels spacedlaterally from said members and mounted upon individual wheel mountings;of driving units carried by and individual to said wheels, powergenerating means mounted on said frame, means-for transmitting powerfrom said generator to eachof said driving units and permitting freemovement of each wheel relative to said frame, and means forindividually and yieldingly connecting each wheel to one of said framemembers, said means including two pairs of arms, the arms of each pairbeing pivotally connected adjacent one end to said frame member and atthe opposite end to said wheel mounting with said arms of each pairextending in parallelism and with said arms of each of said pairs ofarms positioned at opposite sides of the vertical axial plane of saidwheel, one of said arms being extended beyond its pivotal connection tosaid frame member, and yieldable means connected to the extended end ofsaid arm to resist relative vertical movement of said frame and wheel.

' JOHN O. W.

